Triggering answer boxes

ABSTRACT

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for enhancing search results. In one aspect, a method includes receiving a query. A plurality of search results responsive to the query are identified. The search results are analyzed to determine that at least a first search result is associated with a first answer box topic. The search results are provided along with an answer box precursor for the first answer box topic.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/117,993, entitled “Triggering Answer Boxes”, filed May 27, 2011,which claims the benefit under 35 U.S.C. §119(e) of U.S. PatentApplication No. 61/408,538, entitled “Triggering Answer Boxes,” filedOct. 29, 2010, the disclosures of which are expressly incorporatedherein by reference in their entireties.

BACKGROUND

This specification relates to providing information relevant to usersearch queries. Internet search engines identify resources, e.g., webpages, images, text documents, and multimedia content, in response toqueries submitted by users and present information about the resourcesin a manner that is intended to be useful to the users.

Users of search engines are often looking for an answer to a specificquestion, rather than a listing of resources. For example, users maywant to know what the weather is in a particular location, what thedefinition of a particular word is, how to convert between two timezones, or the product of multiplying two numbers. An answer box is auser interface element including a formatted presentation of contentthat is responsive to the query. For example, if the user's query refersto weather in a particular location, a weather answer box can include aforecast of weather in the particular location.

SUMMARY

A search system provides answer boxes with search results. The searchsystem triggers answer boxes by analyzing the search results for answerbox topics. The search system analyzes the search results at search timeor before search time, e.g., by associating resources with answer boxtopics. The search system can use various techniques to determinewhether a resource is associated with any answer box topics, e.g., byparsing the resource according to information from a publisher of theresource or by using a classifier or other system trained using machinelearning techniques.

In general, one innovative aspect of the subject matter described inthis specification can be embodied in methods that include the actionsof receiving a query; receiving a plurality of search results responsiveto the query, each search result identifying a resource responsive tothe query; determining that a first search result is associated with afirst answer box topic by a first publisher of a first resourceidentified by the first search result; and providing the search resultsalong with an answer box precursor for the first answer box topic,wherein the answer box precursor includes information that defines ananswer box. Other embodiments of this aspect include correspondingsystems, apparatus, and computer programs, configured to perform theactions of the methods, encoded on computer storage devices. A system ofone or more computers can be configured to perform particular actions byvirtue of having software, firmware, hardware, or a combination of theminstalled on the system that in operation causes or cause the system toperform the actions. One or more computer programs can be configured toperform particular actions by virtue of including instructions that,when executed by data processing apparatus, cause the apparatus toperform the actions.

These and other embodiments can each optionally include one or more ofthe following features. Determining that the first search result isassociated with the first answer box topic comprises: for each searchresult, accessing an index of search results and determining whether aresource referred to by the result is annotated in the index with ananswer box topic. Determining that the first search result is associatedwith the first answer box topic comprises: for each search result,parsing a resource identified by the search result for answer box topicsaccording to information from a publisher of the resource. The actionsfurther include indexing a plurality of resources to an index; and foreach resource, parsing the resource for answer box topics according toinformation from a publisher of the resource and annotating the resourcein the index with any answer box topics identified by the parsing. Theactions further include determining that a second search result isassociated with another answer box topic, and wherein providing thesearch results along with an answer box precursor for the first answerbox topic comprises selecting the first answer box topic based on thefirst search result having a higher ranking position relative to thesecond search result in the plurality of search results. The actionsfurther include determining that a second search result is associatedwith another answer box topic, and wherein providing the search resultsalong with an answer box precursor for the first answer box topiccomprises selecting the first answer box topic based on one or morestrength of association scores for the first and second search results.The actions further include obtaining the answer box precursor for thefirst answer box topic using a mapping between a plurality of answer boxtopics and answer box precursors. The actions further include receivingthe answer box precursor for the first answer box topic from the firstpublisher. The answer box precursor includes content provided by thefirst publisher for the answer box. The answer box precursor includescode for obtaining content from a publisher server for the firstpublisher. The answer box is a user interface element including aformatted presentation of content. Determining that the first searchresult is associated with the first answer box topic comprises analyzingthe first resource using predefined information regarding the structureof the first resource or a resource locator for the first resource. Thefirst search result is associated with the first answer box topiccomprises identifying one or more ads associated with the first resourceand determining that at least one of the ads is associated with thefirst answer box topic. Receiving the query comprises receiving thequery from a user device, and providing the search results comprisessending a document including the search results to the user device.Determining that the first search result is associated with the firstanswer box topic comprises using entity-extraction techniques to extractthe first answer box topic from the first resource.

Particular embodiments of the subject matter described in thisspecification can be implemented so as to realize one or more of thefollowing advantages. A search system can present answer boxes withsearch results that are more likely to be relevant to a user's searchthan answer boxes presented using conventional techniques that selectanswer boxes using only search queries. A search system can triggerrelevant answer boxes more frequently than search systems usingconventional triggering techniques. If multiple answer boxes arerelevant to a user's search, search results can be analyzed to determinewhich answer boxes are most relevant to the user's search. For example,for a query potentially relating to multiple topics, the search resultsfor the query can be analyzed to determine which topic is most likelyrelevant to the user's search. Answer boxes can be personalized toparticular users by triggering answer boxes based on personalized searchresults.

The details of one or more embodiments of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages of thesubject matter will become apparent from the description, the drawings,and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a search user interface as displayed in an examplegraphical user interface (GUI) as presented in a web browser.

FIG. 2 is a flow diagram of an example process for providing an answerbox with search results.

FIG. 3 is a block diagram of a search system for providing answer boxes.Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

FIG. 1 illustrates a search user interface as displayed in an examplegraphical user interface (GUI) 100 as presented in a web browser. TheGUI 100 includes a text entry field 102 which accepts users' queriesthat are transmitted to a search engine when a search button 104 isselected. The search engine identifies resources (e.g., web pages) thatare responsive to the query in an index of resources of the world wideweb or other collection of resources and then transmits search resultsto the web browser for presentation. Each search result includes a linkto a corresponding resource and some information about the resource,e.g., a snippet extract from the resource or a title.

A resource is any data that can be provided over a network and that isassociated with a resource address, e.g., a Uniform Resource Identifier(URI) or, more specifically, a Uniform Resource Locator (URL). Resourcesmay be Hypertext Markup Language (HTML) pages, word processingdocuments, portable document format (PDF) documents, electronic books,audio content, images, videos, electronic games, or feed sources.

FIG. 1 shows an example search results page for the query “duke bluedevils.” The page includes an answer box 106 and two search results 108and 110. The answer box 106 and search results 108 and 110 areresponsive to the query. The search engine selects the answer box 106based on the search results 108 and 110 and populates it. The answer box106 shows scores of football games played by the Duke Universityfootball team. The search engine selects an answer box that showsfootball scores even though the query does not explicitly indicate aninterest in football. To determine whether to show an answer box forfootball as opposed to one for basketball or another sport, the searchengine analyzes the search results 108 and 110.

The search engine identifies the search results 108 and 110, forexample, using conventional search techniques. For example, conventionalsearch techniques may identify results for the Duke football team asbeing particularly relevant during football season and results for theDuke basketball team, during basketball season. In FIG. 1, a top searchresult 110 is related to the Duke football team, thus the search enginetriggers an answer box for football scores. By analyzing the searchresults to trigger answer boxes, the search engine can trigger answerboxes for football scores during football season and answer boxes forbasketball scores during basketball season.

FIG. 2 is a flow diagram of an example process 200 for providing ananswer box with search results. In some implementations, a system of oneor more computers performs the process 200. For convenience, the processwill be described with respect to a system that performs the process200.

The system receives a query (step 202). For example, the query may bereceived from a user operating a client program on a user device. Thesystem identifies search results responsive to the query (step 204). Thesystem identifies responsive search results, for example, usingconventional search techniques.

In some implementations, the search results are customized to aparticular user. For example, the search results may be customized basedon a user's specified preferences or search history. In systems that useuser search history, users may be given an opportunity to opt in or outof features that collect search history. In addition, certain searchhistory data may be anonymized in one or more ways before it is storedor used, so that personally identifiable information is removed. Forexample, a user's identity may be anonymized so that the no personallyidentifiable information can be determined for the user, or a user'sgeographic location may be generalized, so that a particular location ofa user cannot be determined. Because the search results can becustomized to a particular user, an answer box selected using thecustomized search results can also be customized to a particular user.

The system analyzes the search results for answer box topics (step 206).A number of methods for determining whether answer box topics areassociated with search results are described below with reference to theanswer box topic selector 324 shown in FIG. 3. For example, the systemmay analyze each of a number of the top-ranked search results todetermine whether the search result is associated with an answer boxtopic. An answer box topic is a topic for which answer boxes areavailable. Example answer box topics that a search system could supportinclude sports, sports teams, sports players, television shows, movies,celebrities, weather, and finance.

Determining whether a search result is associated with an answer boxtopic is described further below with reference to FIG. 3. In someimplementations, the search results are pre-annotated with associatedanswer box topics. In those implementations, the system analyzes thesearch results to determine which of them are annotated with answer boxtopics. In some implementations, the system analyzes the search resultsat search time to determine which of them are associated with answer boxtopics.

The system selects an answer box matching an answer box topic determinedto be associated with one or more of the search results (step 208). Insome implementations, the system selects an answer box matching ahighest ranking search result associated with an answer box topic. Forexample, if the system determines that two of the search results areassociated with two different answer box topics, the system may selectan answer box for the answer box topic associated with the higherranking search result. In some implementations, the system selects ananswer box topic based on the number of search results associated withthe answer box topic. For example, if the system determines that a firstanswer box topic is associated with one search result and a secondanswer box topic is associated with two search results, the system mayselect the second answer box topic because it is associated with moresearch results than the first answer box topic.

In various implementations, the system selects an answer box topic basedon scores assigned to the search results that represent the strength ofthe associations between search results and answer box topics. Assigningscores representing the strength of associations is discussed furtherbelow with reference to FIG. 3.

The system obtains an answer box precursor for the selected answer box(step 210). An answer box is created from an answer box precursor. Ananswer box precursor includes information that defines an answer box. Ananswer box precursor typically includes formatting information orcontent or both. For example, an answer box precursor may include atemplate or a script, to which particular values are added, or code thatobtains particular values when executed. An answer box precursor mayinclude a multimedia object, e.g., a digital image or video.

In some implementations, the system obtains the selected answer boxprecursor using a mapping between answer box topics and answer boxprecursors. The system obtains the answer box precursor and, in somecases, information required for the particular answer box precursor.Table 1 illustrates an example mapping between example answer box topicsand answer box precursors.

TABLE 1 Topic Answer Box Precursor Duke football Information defining atable of rows and columns for scores of games and resource locations ongoduke.com for data of scores and games Pollen counts Informationdefining a bar graph of recent pollen counts for display and resourcelocations on weather.com for data on pollen counts MultiplicationExecutable code to perform multiplication (e.g., when executed by thesystem, or by a client system)

The system can obtain the mapping between answer box topics and answerbox precursors, and the answer box precursors themselves, from varioussources. For example, a system administrator may define some of themapping information and some of the answer box precursors. In someimplementations, mapping information is provided by publishers.

For example, a publisher of information on Duke football can providemapping information from the topic “Duke football” to sources ofinformation on the publisher's server at goduke.com. The publisher canprovide the mapping information to a system administrator or provide theinformation without administrator review, e.g., by including theinformation with a web page available to the system. In cases where theanswer box precursor specifies information to retrieve and present withthe answer box, the system can obtain the specified information eitherat search time or before search time (e.g., by storing the specifiedinformation for use at search time).

The system provides the search results and the answer box precursor(step 212). For example, if the query is received from a program on auser computer, the system may send the answer box precursor to the usercomputer so that the user computer can present the answer box in theprogram along with the search results.

FIG. 3 is a block diagram of a search system 302 for providing answerboxes. The search system 302 includes one or more computers. The searchsystem 302 communicates with user devices 310 and publisher servers 312over a data communication network 314. A user can send search queries tothe search system 302 using a user device 310, e.g., a personal computeror smart phone running a web browser. The search system 302 responds bysending search results to the user device 310, e.g., for presentation ina web browser. In some cases, the search system 302 sends one or moreanswer boxes with the search results. A publisher server 312 is one ormore computers that host and provide electronic access to a resource byuse of the network 314. A publisher server 312 typically hosts a website that is a collection of one or more resources associated with adomain name. An example web site is a collection of web pages formattedin hypertext markup language (HTML) that can contain text, graphicimages, multimedia content, and programming elements, such as scripts.

The search system includes a search engine 304. The search engine 304identifies resources relevant to queries. The search engine 304 includesan indexing engine that crawls the publisher servers 312 and indexes theresources provided by the publisher servers 312. The index informationis stored in an index database 316. In general, the index database 316can include various types of indexes for resources, includingkeyword-based indexes, location-based indexes, and other indexes. Thesearch engine 304 also includes a ranking engine 308 that ranksresources, e.g., by quality, by relevancy to a query, or both.

The search system 302 includes a result-topic matching engine 318. Theresult-topic matching engine 318 receives search results from the searchengine 304 and determines whether any of the search results areassociated with answer box topics stored in a repository of answer boxtopics 320. The answer box topics repository 320 is populated withanswer box topics by a system administrator (e.g., as specified by apublisher) or by the indexing engine 306 when it indexes resources thatindicate that they are associated with answer box topics. Some answerbox topics relate to content that can be computed rather than read froma data source; for example, mathematical formulae, sunrise/sunset times,and so on. Some answer box topics relate to data gathered by a systemadministrator and stored in, e.g., a database.

The search system 302 includes an answer box engine 322 that obtainsanswer boxes for answer box topics. For example, the answer box engine322 may obtain answer boxes using a mapping between answer box topicsand answer box formats as described above with reference to FIG. 2.

The search system 302 includes an answer box topic selector 324. Theselector 324 analyzes resources for answer box topics. The selector 324determines whether to associate a given resource with an answer boxtopic from the answer box topics repository 320. The selector 324 canuse various techniques to determine whether a resource should beassociated with an answer box topic. For example, the answer box topicselector 324 may parse a resource according to information provided by apublisher of the resource, e.g., a page template or schema. The answerbox topic selector 324 can be implemented using any combination of anyor all of the following implementations.

In some implementations, the selector 324 is configured to analyzeresources from one or more domains. The selector 324 uses predefinedinformation regarding the structure of a resource from one of thedomains to determine an answer box topic for the resource. For example,the selector 324 may be configured for a web site at nbaplayers.com.Given a resource having a resource address of“http://nbaplayers.com/player/Joe_Random,” the selector determines thatthe resource is associated with an answer box topic for the player “JoeRandom.”

In some implementations, a system administrator configures the selector324. For example, the system administrator may use information from apublisher for resources provided by the publisher's server. In someimplementations, the search system 302 in addition or as an alternativeuses machine learning techniques to configure the selector 324. Forexample, the search system 302 may train a classifier using a set ofresources associated with various answer box topics, e.g., using any ofthe other techniques for analyzing resources mentioned in thisspecification. The set of resources can be used as a labeled set ofexamples for supervised or reinforcement learning; alternatively, othermethods, e.g., unsupervised or semi-supervised learning techniques canbe applied.

In some implementations, the selector 324 analyzes resources usinggeneral information that is not specific to a domain. For example, for aweb page, the selector 324 may analyze metadata tags, titles, and otherinformation indicative of topics for the web page. In another example,for an image, the selector 324 may analyze contextual text (e.g., acaption for the image, metadata for the image, text of a web pageincluding the image) for information indicative of a topic.

In some implementations, the selector 324 analyzes advertisementsassociated with a resource for answer box topics, e.g., by matching keywords in the advertisements with key words for the answer box topics.For example, the selector 324 may use an ads engine 326 to identify adsassociated with a resource. The ads engine 326 uses, e.g., conventionaltechniques to identify ads from an ads repository 328 to associate withresources.

In some implementations, the selector 324 determines queries that, whensearched for, cause a resource to appear in search results. For example,the selector 324 may use logs recorded by the search engine 304 todetermine queries that lead to the resource being included in searchresults. Query log data may be anonymized. The selector 324 thenanalyzes the queries to determine answer box topics to associate withthe resource. For example, the selector 324 may match terms of thequeries with key words for answer box topics.

In some implementations, the selector 324 uses entity-extractiontechniques to analyze resources for answer box topics. For example, thesystem may locate and classify elements of text (e.g., words or phrases)into predefined categories and then compare the categories with answerbox topics. The system may use linguistic grammar-based techniques,statistical models (e.g., based on training data), and other techniques.

In some implementations, the selector 324 assigns scores to the searchresults that represent the strength of the associations between searchresults and answer box topics. For example, the selector 324 may assigna relatively large strength of association score to a search resultidentifying a web page titled “LeBron James” for the answer box topicfor LeBron James and a relatively small strength of association score toa search result identifying a web page only including a single referenceto LeBron James for the answer box topic for LeBron James.

The search system 302 uses the result-topic matching engine 318, theanswer box engine 322, and the answer box topic selector 324 to provideanswer boxes with search results. In some implementations, the indexingengine 306 uses the answer box topic selector 324 to determine answerbox topics for resources at index time. For example, the indexing engine306 may annotate resources in the index database 316 with answer boxtopics determined using the answer box topic selector 324. In some otherimplementations, the search system 302 annotates resources with answerbox topics independently from the indexing process but before searchtime. In some other implementations, the search system 302 analyzesresources for answer box topics using the answer box topic selector 324at search time.

Embodiments of the subject matter and the operations described in thisspecification can be implemented in digital electronic circuitry, or incomputer software, firmware, or hardware, including the structuresdisclosed in this specification and their structural equivalents, or incombinations of one or more of them. Embodiments of the subject matterdescribed in this specification can be implemented as one or morecomputer programs, i.e., one or more modules of computer programinstructions, encoded on computer storage medium for execution by, or tocontrol the operation of, data processing apparatus. Alternatively or inaddition, the program instructions can be encoded on anartificially-generated propagated signal, e.g., a machine-generatedelectrical, optical, or electromagnetic signal, that is generated toencode information for transmission to suitable receiver apparatus forexecution by a data processing apparatus. A computer storage medium canbe, or be included in, a computer-readable storage device, acomputer-readable storage substrate, a random or serial access memoryarray or device, or a combination of one or more of them. Moreover,while a computer storage medium is not a propagated signal, a computerstorage medium can be a source or destination of computer programinstructions encoded in an artificially-generated propagated signal. Thecomputer storage medium can also be, or be included in, one or moreseparate physical components or media (e.g., multiple CDs, disks, orother storage devices).

The operations described in this specification can be implemented asoperations performed by a data processing apparatus on data stored onone or more computer-readable storage devices or received from othersources.

The term “data processing apparatus” encompasses all kinds of apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, a system on a chip, or multipleones, or combinations, of the foregoing The apparatus can includespecial purpose logic circuitry, e.g., an FPGA (field programmable gatearray) or an ASIC (application-specific integrated circuit). Theapparatus can also include, in addition to hardware, code that createsan execution environment for the computer program in question, e.g.,code that constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, a cross-platform runtimeenvironment, a virtual machine, or a combination of one or more of them.The apparatus and execution environment can realize various differentcomputing model infrastructures, such as web services, distributedcomputing and grid computing infrastructures.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, object, orother unit suitable for use in a computing environment. A computerprogram may, but need not, correspond to a file in a file system. Aprogram can be stored in a portion of a file that holds other programsor data (e.g., one or more scripts stored in a markup languagedocument), in a single file dedicated to the program in question, or inmultiple coordinated files (e.g., files that store one or more modules,sub-programs, or portions of code). A computer program can be deployedto be executed on one computer or on multiple computers that are locatedat one site or distributed across multiple sites and interconnected by acommunication network.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform actions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application-specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. The essential elements of a computer area processor for performing actions in accordance with instructions andone or more memory devices for storing instructions and data. Generally,a computer will also include, or be operatively coupled to receive datafrom or transfer data to, or both, one or more mass storage devices forstoring data, e.g., magnetic, magneto-optical disks, or optical disks.However, a computer need not have such devices. Moreover, a computer canbe embedded in another device, e.g., a mobile telephone, a personaldigital assistant (PDA), a mobile audio or video player, a game console,a Global Positioning System (GPS) receiver, or a portable storage device(e.g., a universal serial bus (USB) flash drive), to name just a few.Devices suitable for storing computer program instructions and datainclude all forms of non-volatile memory, media and memory devices,including by way of example semiconductor memory devices, e.g., EPROM,EEPROM, and flash memory devices; magnetic disks, e.g., internal harddisks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROMdisks. The processor and the memory can be supplemented by, orincorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subjectmatter described in this specification can be implemented on a computerhaving a display device, e.g., a CRT (cathode ray tube) or LCD (liquidcrystal display) monitor, for displaying information to the user and akeyboard and a pointing device, e.g., a mouse or a trackball, by whichthe user can provide input to the computer. Other kinds of devices canbe used to provide for interaction with a user as well; for example,feedback provided to the user can be any form of sensory feedback, e.g.,visual feedback, auditory feedback, or tactile feedback; and input fromthe user can be received in any form, including acoustic, speech, ortactile input. In addition, a computer can interact with a user bysending documents to and receiving documents from a device that is usedby the user; for example, by sending web pages to a web browser on auser's user computer in response to requests received from the webbrowser.

Embodiments of the subject matter described in this specification can beimplemented in a computing system that includes a back-end component,e.g., as a data server, or that includes a middleware component, e.g.,an application server, or that includes a front-end component, e.g., aclient computer having a graphical user interface or a Web browserthrough which a user can interact with an implementation of the subjectmatter described in this specification, or any combination of one ormore such back-end, middleware, or front-end components. The componentsof the system can be interconnected by any form or medium of digitaldata communication, e.g., a communication network. Examples ofcommunication networks include a local area network (“LAN”) and a widearea network (“WAN”), an inter-network (e.g., the Internet), andpeer-to-peer networks (e.g., ad hoc peer-to-peer networks).

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other. In someembodiments, a server transmits data (e.g., an HTML page) to a usercomputer (e.g., for purposes of displaying data to and receiving userinput from a user interacting with the user computer). Data generated atthe user computer (e.g., a result of the user interaction) can bereceived from the user computer at the server.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinventions or of what may be claimed, but rather as descriptions offeatures specific to particular embodiments of particular inventions.Certain features that are described in this specification in the contextof separate embodiments can also be implemented in combination in asingle embodiment. Conversely, various features that are described inthe context of a single embodiment can also be implemented in multipleembodiments separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the embodiments described above should not be understoodas requiring such separation in all embodiments, and it should beunderstood that the described program components and systems cangenerally be integrated together in a single software product orpackaged into multiple software products.

Thus, particular embodiments of the subject matter have been described.Other embodiments are within the scope of the following claims. In somecases, the actions recited in the claims can be performed in a differentorder and still achieve desirable results. In addition, the processesdepicted in the accompanying figures do not necessarily require theparticular order shown, or sequential order, to achieve desirableresults. In certain implementations, multitasking and parallelprocessing may be advantageous.

What is claimed is:
 1. (canceled)
 2. A method performed by dataprocessing apparatus, the method comprising: receiving a query from auser device; receiving data identifying a plurality of resourcesdetermined to be responsive to the query, wherein each of the resourcesis also determined to be associated with a respective answer box topic;determining a set of answer box topics from the respective answer boxtopics associated with the resources; analyzing each answer box topic ofthe set of answer box topics to identify a first answer box topic thatis responsive to the query; obtaining an answer box precursor for thefirst answer box topic using a mapping between a plurality of answer boxtopics and a plurality of answer box precursors, wherein the answer boxprecursor includes information that defines an answer box; andproviding, to the user device, the answer box precursor for the firstanswer box topic in response to the query.
 3. The method of claim 2,further comprising: indexing the plurality of resources to an index; andfor each resource, parsing the resource for answer box topics accordingto information from a publisher of the resource and annotating theresource in the index with any answer box topics identified by theparsing.
 4. The method of claim 2, further comprising: identifying, bythe data processing apparatus, a second answer box topic that isresponsive to the query, and wherein providing further comprisesselecting, by the data processing apparatus, the first answer box topicas a consequence of a resource associated with the first answer boxtopic having a higher ranking relative to a reference associated withthe second answer box topic.
 5. The method of claim 2, wherein themapping includes mapping information provided by a publisher of aresource associated with the first answer box topic, the method furthercomprising receiving the answer box precursor for the first answer boxtopic from the publisher.
 6. The method of claim 2, wherein the answerbox precursor includes information that defines an answer box, whereinthe answer box is a user interface element including a formattedpresentation of content.
 7. The method of claim 2, wherein analyzingeach answer box topic further comprises analyzing a first resourceassociated with the first answer box topic using predefined informationregarding a structure of the first resource or a resource locator forthe first resource.
 8. The method of claim 2, wherein analyzing eachanswer box topic further comprises using entity-extraction techniques toextract the first answer box topic from the first resource.
 9. A systemcomprising one or more computers configured to perform operationscomprising: receiving a query from a user device; receiving dataidentifying a plurality of resources determined to be responsive to thequery, wherein each of the resources is also determined to be associatedwith a respective answer box topic; determining a set of answer boxtopics from the respective answer box topics associated with theresources; analyzing each answer box topic of the set of answer boxtopics to identify a first answer box topic that is responsive to thequery; obtaining an answer box precursor for the first answer box topicusing a mapping between a plurality of answer box topics and a pluralityof answer box precursors, wherein the answer box precursor includesinformation that defines an answer box; and providing, to the userdevice, the answer box precursor for the first answer box topic inresponse to the query.
 10. The system of claim 9, the operations furthercomprising: indexing the plurality of resources to an index; and foreach resource, parsing the resource for answer box topics according toinformation from a publisher of the resource and annotating the resourcein the index with any answer box topics identified by the parsing. 11.The system of claim 9, the operations further comprising: identifying,by the data processing apparatus, a second answer box topic that isresponsive to the query, and wherein providing further comprisesselecting, by the data processing apparatus, the first answer box topicas a consequence of a resource associated with the first answer boxtopic having a higher ranking relative to a reference associated withthe second answer box topic.
 12. The system of claim 9, wherein themapping includes mapping information provided by a publisher of aresource associated with the first answer box topic, the method furthercomprising receiving the answer box precursor for the first answer boxtopic from the publisher.
 13. The system of claim 9, wherein the answerbox precursor includes information that defines an answer box, whereinthe answer box is a user interface element including a formattedpresentation of content.
 14. The system of claim 9, wherein analyzingeach answer box topic further comprises analyzing a first resourceassociated with the first answer box topic using predefined informationregarding a structure of the first resource or a resource locator forthe first resource.
 15. The system of claim 9, wherein analyzing eachanswer box topic further comprises using entity-extraction techniques toextract the first answer box topic from the first resource.
 16. Acomputer storage medium encoded with a computer program, the programcomprising instructions that when executed by data processing apparatuscause the data processing apparatus to perform operations comprising:receiving a query from a user device; receiving data identifying aplurality of resources determined to be responsive to the query, whereineach of the resources is also determined to be associated with arespective answer box topic; determining a set of answer box topics fromthe respective answer box topics associated with the resources;analyzing each answer box topic of the set of answer box topics toidentify a first answer box topic that is responsive to the query;obtaining an answer box precursor for the first answer box topic using amapping between a plurality of answer box topics and a plurality ofanswer box precursors, wherein the answer box precursor includesinformation that defines an answer box; and providing, to the userdevice, the answer box precursor for the first answer box topic inresponse to the query.
 17. The computer storage medium of claim 16, theoperations further comprising: indexing the plurality of resources to anindex; and for each resource, parsing the resource for answer box topicsaccording to information from a publisher of the resource and annotatingthe resource in the index with any answer box topics identified by theparsing.
 18. The computer storage medium of claim 16, the operationsfurther comprising: identifying, by the data processing apparatus, asecond answer box topic that is responsive to the query, and whereinproviding further comprises selecting, by the data processing apparatus,the first answer box topic as a consequence of a resource associatedwith the first answer box topic having a higher ranking relative to areference associated with the second answer box topic.
 19. The computerstorage medium of claim 16, wherein the mapping includes mappinginformation provided by a publisher of a resource associated with thefirst answer box topic, the method further comprising receiving theanswer box precursor for the first answer box topic from the publisher.20. The computer storage medium of claim 16, wherein the answer boxprecursor includes information that defines an answer box, wherein theanswer box is a user interface element including a formattedpresentation of content.
 21. The computer storage medium of claim 16,wherein analyzing each answer box topic further comprises analyzing afirst resource associated with the first answer box topic usingpredefined information regarding a structure of the first resource or aresource locator for the first resource.